System and method for partitioning streaming data coded with fine granularity scalability of use in a cable network

ABSTRACT

System and method for partitioning data on a SCDMA cable network use methods of creating data streams to transmit to a head end. Further, the data streams transmitted to the head end are coded with fine granularity scalability features and contain divisions which are assigned codes based on predetermined criteria, so that in the event certain assigned codes are interrupted from service, all appliances along the network can be serviced without interruption.

PRIORITY CLAIM

[0001] The present application is related to and claims the priority ofU.S. Provisional Application No. 60/380,861 filed May 17, 2002, in thenames of FANG-CHU CHEN AND SHANG-CHIH MA, and titled FGS OVER SCDMA BYSTREAM-CODE PARTITION, the entire contents of which are fullyincorporated herein by reference.

DESCRIPTION OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The field of this invention relates generally to cable networkand, more specifically, to partitioning multimedia-streaming data over acable modem.

[0004] 2. Background of the Invention

[0005] In computer networking today, subscribers on a network gain andshare information, accessible by the network, through a service thatprovides access to the network. For each connected subscriber, severaltypes of appliances may be used to access and share this network andinformation. Appliances may include personal computers, televisions,interactive gaming systems, and telephones. Cable networks connect tothese appliances through a subscriber unit, such as a cable modem, to ahead end, or through a service provider, which in turn connects thesubscriber unit to the network and other subscribers located thereon. Asthe appliances communicate and transmit data, the subscriber unit relaysthe data to the head end, which transmits the data to the intendeddestination. The manner in which that data is sent and thecharacteristics of the data, such as the formatting, may have asignificant impact on the speed of data transmissions on the network andthe effectiveness of the head end to service all the appliancesconnected to the network.

[0006] Currently, Synchronous Code Division Multiple Access (S-CDMA) canbe used for data transmission across cable networks. Using S-CDMA hasadvantages. For example, S-CDMA scatters or spreads digital data acrossa wide frequency band, so that multiple subscribers on the network maytransmit and receive data at the same time, while allowing the datatransmission to be secure and resistant to noise. Code Division MultipleAccess (CDMA), on which S-CDMA is based, codes the signal so that asubscriber, associated with a particular code, may decode andreconstruct the signal. Issues may arise where it is required to preventsome appliances from transmitting along the network. In particular,these issues arise when the head end is processing applicationsinvolving multi-media streaming, as these types of applications caninvolve large amounts of bandwidth. Processing large applications candisrupt the effectiveness of the head end to service all the subscribersand appliances on the network.

[0007] One technique for increasing the efficiency of the network is forthe head end to assign predetermined levels of importance, or codes, tothe data according to the source or appliance generating that data. Thedesired effect is that when network traffic gets too congested,appliances with a lower importance level are not serviced until thetraffic becomes less congested. This leads to many possible problems,such as delays in servicing some appliances, or in some cases,termination of service to some appliances.

[0008] S-CDMA transmitters, which convert data into a format suitablefor transmission, are of the type suggested in the Data Over CableSystems Interface Specifications (DOCSIS) 2.0, Radio Frequency InterfaceSpecification, SP-RFIv2.0-101-011231. DOCSIS 2.0 is an industry standardrelating to radio frequency interface specifications for cable networks.Specifically, input data, in S-CDMA format, on the transmitter is codedby channel and framed. Thereafter, the data is spread over one or morecodes selected from a predetermined code set. After spreading, the datais converted to analog form, filtered, and modulated into a radiofrequency (RF) signal which is transmitted to the head end through acoaxial cable.

[0009] In a cable network, the total uplink bandwidth on the cable isshared by all the subscriber units connected to the cable. Since thedata traveling on the cable is changing over time, the head end has theauthority to dynamically change the bandwidth allocated for eachsubscriber unit. In terms of an S-CDMA system, changing bandwidth meansthat the head end changes the number of codes assigned to eachsubscriber. When codes are assigned on a stream-by-stream basis and thehead end instructs the subscriber unit to interrupt service for aparticular code, problems may occur in continuing services of thestreams associated with that code.

[0010] In non-cable network applications, techniques such as FineGranular Scalabiltity (FGS), which provide flexibility in adjusting bitrates of the data, have been used to combat the problem of data trafficcongestion on a network. In FGS, every encoded bit has two layers orsections: a base layer and an enhancement layer. As an inherent propertyof FGS encoding, the base layer must be received. On the other hand, theenhancement layer does not have to be received, or in the alternative,only partially received. The overall quality of the signal, however,depends upon the length of the enhancement layer received so that, asmore of the enhancement layer is received, an increase is observed inthe decoded stream's quality.

[0011] Currently, incorporating FGS on a cable network using S-CDMA hasproblems. In a typical S-CDMA system, levels of importance are assignedon a stream-by-stream basis, or in other words, based on the source ofthe data. FGS is not a suitable choice to remedy the problems discussedearlier, such as the interruption of service to some appliances.Specifically, in an S-CDMA system, each source stream is assigned acode, and this causes difficulty in managing bandwidth on the cableamong multiple appliances. Because the head end is allowed todynamically change the bandwidth for a subscriber unit, which meansreallocating the assigned codes, the subscriber unit should be able torespond quickly in order for the cable network to effectively operate.If a stream is assigned a code, the subscriber unit response could becomplex. For example, if the head end directs that a certain code willnot be available, the stream, and the associated service, may have tostop. Therefore, in order for all streams to be serviced withouttermination of service to some sources, the source of data associatedwith the non-available code will have to share the code with othersources. This involves redesign of the framing process, a process usedto format data, so that the data is suitable for transmission accordingto the protocols of the network. Consequently, communications betweenthe higher layers of the subscriber unit and the head end will,undesirably, need to increase in order to ensure that the subscriberunit and the head end are configured properly with respect to eachother. Moreover, since streams share codes and thus share bandwidth aswell, a bit rate associated with a particular stream is not preservedafter re-assignation of the codes.

SUMMARY OF THE INVENTION

[0012] In accordance with the invention, a method for partitioninginformation on a cable network, including one or more appliances anddata associated with each transmitting appliance, wherein the associateddata comprises a bit rate and a frame length, said method comprisingcreating a source stream, corresponding to each transmitting applianceand representing a continuous form of the associated data, containing atleast one segment, wherein each segment is associated with one of thetransmitting appliances and is assigned a code indicating apredetermined level of importance; creating a partition stream,corresponding to each segment, containing at least one block, whereineach block represents an amount of time in relation to the bit rate andframe length of the associated data; and creating a code stream,corresponding to each block with the same assigned code, and containingat least one coded frame, wherein each frame represents an amount oftime to process one block from every source stream.

[0013] Also, in accordance with the invention, a system for partitioninginformation on a cable network, wherein the cable network includes oneor more appliances and data associated with each transmitting appliance,wherein the data comprises a bit rate and a frame length, said systemcomprising: means for creating source streams, corresponding to eachtransmitting appliance and representing a continuous form of theassociated data, containing at least one segment, wherein each segmentis associated with one of the transmitting appliances and is assigned acode indicating a predetermined level of importance; means for creatingpartition streams, corresponding to each segment, containing at leastone block, wherein each block represents an amount of time in relationto the bit rate and frame length of the associated data; and means forcreating code streams, corresponding to each block with the sameassigned code, and containing at least one coded frame, wherein eachframe represents an amount of time to process one block from everysource stream.

[0014] Additional features and advantages of the invention will be setforth in part in the description which follows, and in part will beobvious from the description, or may be learned by practice of theinvention. The features and advantages of the invention will be realizedand attained by means of the elements and combinations particularlypointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description, serve to explain theprinciples of the invention. In the drawings:

[0016]FIG. 1 is a simplified block diagram of a cable system.

[0017]FIG. 2 is a schematic representation of source data streams, eachof the length of one data frame, used on the cable system of FIG. 1.

[0018]FIG. 3 is a schematic representation of source streams constructedfrom the frames of FIG. 2.

[0019]FIG. 4 is a schematic representation of partition streamsconstructed from the source streams of FIG. 3.

[0020]FIG. 5 is a schematic representation of partitioning of partitionstreams of FIG. 4 into blocks.

[0021]FIG. 6 is a schematic representation of code streams and thestructure of S-CDMA frames constructed from the streams of FIG. 5.

[0022]FIG. 7 is a schematic representation of an FGS signal constructedto be used in a system and method for partitioning streaming data codedwith FGS over a cable network.

[0023]FIG. 8 is a flow chart illustrating a method for partitioningstreaming data coded with FGS over a cable network.

[0024] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

DESCRIPTION OF THE EMBODIMENTS

[0025] Referring now to the drawings, in which the same referencenumbers will be used throughout the drawings to refer to same or likeparts, FIG. 1 is a block diagram of a cable system 100. System 100includes a number X of appliances 102 ₁-102 _(X) connected to asubscriber unit 104, which in turn is connected to a head end 106.Appliances 102 ₁-102 _(X) may include devices such as interactivetelevisions, personal computers, video conference units, telephones, andinteractive gaming systems. Subscriber unit 104 includes a time divisionprocessor 108, a framer 110, and a spreader 112. In addition, timedivision processor 108 creates a time division multiplexed (TDM) signal114, framer 110 creates a code domain signal 116 from N codes 118 ₁-118_(N), and spreader 112 creates a spread signal 120.

[0026] In system 100, signals from appliances 102 ₁-102 _(X) are sent tosubscriber unit 104, where each signal is processed by time divisionprocessor 108 to create TDM signal 114. TDM signal 114 represents datasent from appliances 102 ₁-102 _(X), wherein each of appliances 102₁-102 _(X) has a dedicated time for service within TDM signal 114. TDMsignal 114 may be subject to other conditioning by division processor108, such as channel coding, scrambling, buffering, or amplification.Framer 110 receives TDM signal 114 and converts TDM signal 114 into codedomain signal 116. Framer 110 is a device which conditions and controlsan incoming signal so that the data fields (i.e., addresses, data, errorchecking information) associated with the incoming data stream can beconfigured to transmit along the network in compliance with protocolscharacteristic of the network. Specifically, framer 110 assigns codes118 ₁-118 _(N) to portions of TDM signal 114 according to predeterminedcriteria. Once codes 118 ₁-118 _(N) are assigned to portions of TDMsignal 114, code domain signal 116 is formed. The predetermined criteriamay include establishing an importance level based on the position ofthe data within TDM signal 114 (e.g., based on the source of the data).For example, codes 118 ₁-118 _(N) may be assigned according to which ofappliances 102 ₁-102 _(X) generated the signal being processed. Further,it may be desirable, in the event of heavy data traffic congestion, toterminate service from a personal computer, so that an interactivetelevision may transmit. In this case, the personal computer would beassigned one of codes 118 ₁-118 _(N) indicating a lower importance thanone of codes 118 ₁-118 _(N) assigned to the interactive television, andhead end 106 may determine that the one of codes 118 ₁-118 _(N) assignedto the personal computer should not be transmitted along the network.

[0027] After framing, code domain signal 116 is sent to spreader 112. Inspreader 112, code domain signal 116 is separated and spread so thatdata is grouped according codes 118 ₁-118 _(N). For example, all dataassociated with code 118 ₁ is grouped together, all data associated withcode 118 ₂ is grouped together, continuing until all data associatedwith code 118 _(X) is grouped together. These groupings are then spreadto form spread signal 120. Spread spectrum signals are distributed overa wide range of frequencies and then collected onto their originalfrequency at the receiver, and allow the signals to be resistant tonoise, interference, and snooping. In other words, data associated withone of appliances 102 ₁-102 _(X) is now grouped according to assignedcodes 118 ₁-118 _(N) and transmitted as a spread spectrum signal to headend 106. Spread signal 120 may be in the form of an S-CDMA signal asdescribed, and incorporated herein, by DOCSIS 2.0.

[0028] Multiplexer 108 and spreader 112 can be of the type found in theDOCSIS 2.0 standard previously discussed and incorporated herein byreference. Framer 110 can be implemented in accordance with the methodsillustrated in FIGS. 2-8.

[0029]FIG. 2 illustrates a number X of frames 202 ₁-202 _(X), eachrepresenting a frame of source data streams generated by one ofappliances 102 ₁-102 _(X), collectively containing X*N segments 204₁₁-204 _(XN) constructed and used in system 100 shown in FIG. 1, whereinX represents the number of appliances 102 ₁-102 _(X) and N representsthe number of codes 118 ₁-118 _(N) assigned by head end 106.

[0030] Thus, frames 202 ₁-202 _(X), in the form of a bit stream, aresent from appliances 102 ₁-102 _(X) of FIG. 1, respectively, tosubscriber unit 104. Typically, frames 202 ₁-202 _(X) represent codedstreaming data transmitted from appliances 102 ₁-102 _(X) and is finitein nature (i.e., there exists a definite time for a beginning and end toeach of frames 202 ₁-202 _(X) generated by each of the appliances 102₁-102 _(X)). Frames 202 ₁-202 _(X) contain segments 204 ₁₁-204 _(XN),which are divisions within frames 202 ₁-202 _(X) and, as shown in FIG.2, are assigned values associated with codes 118 ₁-118 _(N).

[0031]FIG. 3 illustrates a number X of source streams 302 ₁-302 _(X)constructed from frames 202 ₁-202 _(X) of FIG. 2 consecutively generatedin time by the corresponding one of appliances 102 ₁-102 _(X). Sourcestreams 302 ₁-302 _(X) contain segments 204 ₁₁-204 _(XN) and a number Kof frames 304 ₁-304 _(K), wherein X is the number of appliances 102₁-102 _(X), N is the number of codes 118 ₁-118 _(N) assigned by head end106, and K is a number of times that frames 202 ₁-202 _(X) areconsecutively generated.

[0032] Source streams 302 ₁-302 _(X) are a continuous and consecutiverepresentation of frames 202 ₁-202 _(X), respectively. In other words,the structure of frames 202 ₁-202 _(X) are repeated, although theinformation for each of consecutive frames 202 ₁-202 _(X) is different,and connected for each of frames 304 ₁-304 _(K) to form source streams302 ₁-302 _(X). For example, all of frames 304 ₁-304 _(K) are connectedto form source stream 302 ₁, thereby representing a continuous form offrame 202 ₁. All segments 204 ₁₁-204 _(XN), from different frames 202₁-202 _(X) are thus assembled. Segments 204 ₁₁-204 _(XN) are assignedcodes 118 ₁-118 _(N). More particularly, subscriber unit 104 assignscodes 118 ₁-118 _(N) to source streams 302 ₁-302 _(X) according todifferent importance levels in each stream. According to the principlescontained with DOCSIS 2.0, head end 106 assigns codes 118 ₁-118 _(N) tosubscriber unit 104. However, in FIG. 3 head end 106 labels codes 118₁-118 _(N) with, for example, different importance levels and codes 118₁-118 _(N) are assigned to segments 204 ₁₁-204 _(XN) while sourcestreams 302 ₁-302 _(X) are being processed by framer 110. For example,segment 204 ₁₁ associated with source stream 302 ₁ is assigned code 118₁, segment 204 ₁₂ associated with source stream 302 ₁ is assigned code118 ₂, continuing to segment 204 _(1N), which is associated with sourcestream 302 ₁ and is assigned code 118 _(N). This process is repeated forthe rest of source streams 302 ₂-302 _(X). As previously described,codes 118 ₁-118 _(N) may indicate a relative importance level of each ofsegments 204 ₁₁-204 _(XN) contained within the same one of sourcestreams 302 ₁-302 _(X). The length of each of segments 204 ₁₁-204 _(XN),associated with each of appliances 102 ₁-102 _(X), may be different,depending upon the frame length of the corresponding one of sourcestreams 302 ₁-302 _(X). The purpose of having segments 204 ₁₁-204 _(XN)in source streams 302 ₁-302 _(X) is to prioritize data within sourcestreams 302 ₁-302 _(X) transmitted from appliances 102 ₁-102 _(X)according to codes 118 ₁-118 _(N).

[0033] Source streams 302 ₁-302 _(X) may be formed using framer 110 ofFIG. 1.

[0034]FIG. 4 illustrates a number X*N of partition streams 402 ₁₁-402_(XN), constructed from source streams 302 ₁-302 _(X) of FIG. 3.Partition streams 402 ₁₁-402 _(XN) also include segments 204 ₁₁-204_(XN), wherein segments 204 ₁₁-204 _(XN) are associated with codes 118₁-118 _(N). As previously described, X is the number of appliances 102₁-102 _(X) and N is the number of codes 118 ₁-118 _(N) assigned by headend 106.

[0035] Partition streams 402 ₁₁-402 _(XN) are formed to create new datastreams that group segments 204 ₁₁-204 _(XN) associated with codes 118₁-118 _(N) for each of frames 304 ₁-304 _(K). For example, partitionstream 402 ₁₁ includes all segments 204 ₁₁ from frames 304 ₁-304 _(K)(i.e., segment 204 ₁₁ from frame 304 ₁, segment 204 ₁₁ from frame 304 ₂,continuing until segment 204 ₁₁ from frame 304 _(K)). The result is theformation of partition streams 402 ₁₁-402 _(XN) corresponding tosegments 204 ₁₁-204 _(XN), respectively.

[0036] Partition streams 402 ₁₁-402 _(XN), may be formed using framer110 of FIG. 1.

[0037]FIG. 5 further illustrates partition streams 402 ₁₁-402 _(XN) ofFIG. 4. Partition streams 402 ₁₁-402 _(XN) include blocks 502 ₁₁₁-502_(XNZ), wherein X is the number of appliances 102 ₁-102 _(X), N is thenumber of codes 118 ₁-118 _(N) assigned by head end 106, and Zrepresents an index number to associate one of blocks 502 ₁₁₁-502 _(XNZ)to one of X*N partition streams 402 ₁₁-402 _(XN).

[0038] Divisions representing segments 204 ₁₁-204 _(XN) are removed andblocks 502 ₁₁₁-502 _(XNZ) are created in partition streams 402 ₁₁-402_(XN). This is done to ensure that the divisions formerly representingsegments 204 ₁₁-204 _(XN) may be resized within partition streams 402₁₁-402 _(XN) as blocks 502 ₁₁₁-502 _(XNZ). The size of each of blocks502 ₁₁₁-502 _(XNZ) depends upon the bit rate and frame length of thecorresponding source streams 302 ₁-302 _(X). In other words, the bitrates and frame lengths of source streams 302 ₁-302 _(X) generated byappliances 102 ₁-102 _(X) will be preserved, through blocks 502 ₁₁₁-502_(XNZ) in the corresponding partition streams 402 ₁₁-402 _(XN). The sizeof each of blocks 502 ₁₁₁-502 _(XNZ) can be determined by Equation (1):

Block size of 502 _(XNZ)=bit rate of 302 _(X)/S-CDMA frame rate  (1);

[0039] where an S-CDMA frame is associated with one of a number N ofcode streams 602 ₁-602 _(N) as illustrated in FIG. 6 and described morefully below. For example, in partition stream 402 ₁₁, blocks 502 ₁₁,continuing through 502 _(11Z) are created, each having the same length.The length of each of blocks 502 ₁₁₁-502 _(XNZ) correspond to a durationof transmitting time for each of frames 304 ₁-304 _(K), eventuallyreceived by head end 106. The total number of blocks 502 ₁₁₁-502 _(XNZ)for partition streams 402 ₁₁-402 _(XN) is not definite and depends uponthe respective size of each partition stream 402 ₁₁-402 _(XN).

[0040]FIG. 6 illustrates the number N of code streams 602 ₁-602 _(N),which are constructed from partition streams 402 ₁₁-402 _(XN) of FIG. 5.Code streams 602 ₁-602 _(N) further contain blocks 502 ₁₁₁-502 _(XNZ)and SCDMA frames 604 ₁-604 _(L). X represents the number of appliances102 ₁-102 _(X), N is the number of codes 118 ₁-118 _(N) assigned by headend 106, and L represents an index number to associate one of S-CDMAframes 604 ₁-604 _(L) to code streams 602 ₁-602 _(N).

[0041] Blocks 502 ₁₁₁-502 _(XNZ) of FIG. 5 are reallocated so that eachof code streams 602 ₁-602 _(N) comprised from blocks 502 ₁₁₁-502 _(XNZ)correspond to each of codes 118 ₁-118 _(N). For example, when N=1, codestream 602 ₁ contains blocks 502 ₁₁₁-502 _(X1Z), because blocks 502₁₁₁-502 _(X1Z) are associated with code 118 ₁. In other words, for codestream 602 ₁, all blocks corresponding with code 118 ₁ are placed incode stream 602 ₁. These would be blocks 502 ₁₁₁, 502 ₂₁₁, 502 ₃₁₁, andcontinuing until 502 _(X1Z). Thus, as frames 202 ₁-202 _(X) associatedwith appliances 102 ₁-102 _(X) transmit, according to FIGS. 2-6, allappliances 102 ₁-102 _(X) transmit to head end 106, even when head end106 determines that some of codes 118 ₁-118 _(N) should not beprocessed. This results in every one of appliances 102 ₁-102 _(X)sacrificing some bandwidth so that interruption of service is preventedand all of appliances 102 ₁-102 _(X) may transmit.

[0042] Further, under the principles disclosed for S-CDMA in DOCSIS 2.0,an S-CDMA frame may be defined as one of S-CDMA frames 604 ₁-604 _(L),which corresponds to the amount of time to process or service one ofblocks 502 ₁₁₁-502 _(XNZ) from every one of appliances 102 ₁-102 _(X).In other words, as shown in FIG. 6, blocks 502 ₁₁₁-502 _(XNZ) are formedso that in any given one of S-CDMA frames 604 ₁-604 _(L), every one ofappliances 102 ₁-102 _(X) is serviced. This allows equal service to allappliances 102 ₁-102 _(X) without disruption of service to any one ofappliances 102 ₁-102 _(X).

[0043] Code streams 602 ₁-602 _(N) may be formed using framer 110 ofFIG. 1.

[0044]FIG. 7 illustrates a frame of an FGS encoded source streamconstructed to be used in a system and method consistent with thepresent invention for partitioning data for use in a cable network. Anumber X of FGS data streams 702 ₁-702 _(X) respectively contain baselayers 704 ₁-704 _(X) and enhancement layers 706 ₁-706 _(X), wherein Xrepresents the number of appliances 102 ₁-102 _(X).

[0045] Implementing FGS data streams 702 ₁-702 _(X) for the presentsystem and method for partitioning data over a cable network requiresthat each of frames 202 ₁-202 _(X) are encoded to form FGS data streams702 ₁-702 _(X). In order to do that, each of frames 202 ₁-202 _(X)should be encoded to form base layers 704 ₁-704 _(X) and enhancementlayers 706 ₁-706 _(X). Base layers 704 ₁-704 _(X) must be transmitted,as this is a necessary characteristic of FGS encoding. However,enhancement layers 706 ₁-706 _(X) may only be partially sent or not sentat all. FGS data streams 702 ₁-702 _(X) may further contain segments 204₁₁-204 _(XN), with corresponding codes 118 ₁-118 _(N). Accordingly, codestreams 602 ₁-602 _(N) can be formed using the system and methodpreviously discussed. FGS data streams 702 ₁-702 _(X) are coded in sucha manner that information of greater significance is placed ahead ofthat of less significance. Therefore, enhancement layers 706 ₁-706 _(X)can be truncated to any length when the data rate of the source has tobe adjusted due to variation of available bandwidth determined by headend 106. FGS data streams 702 ₁-702 _(X) may be transmitted over anS-CDMA system as described, and incorporated herein by reference, by theDOCSIS 2.0 standard.

[0046] FGS data streams 702 ₁-702 _(X) are generated by eachcorresponding appliance 102 ₁-102 _(X) of FIG. 1. When FGS data streams702 ₁-702 _(X) are ready for transmission to head end 106, FGS datastreams 702 ₁-702 _(X) are framed according to the process outlined inFIGS. 2-6 and then spread across a radio frequency band, which may beimplemented using spreader 112, and simultaneously transmitted to headend 106.

[0047]FIG. 8 is a flow chart 800 illustrating a method for partitioninginformation over a cable network. At stage 802, appliances 102 ₁-102_(X) transmit FGS-coded streaming data to subscriber unit 104. The datacan be in the form of bit stream frames, such as frames 202 ₁-202 _(X).An example of the information that can flow from appliances 102 ₁-102_(X) to subscriber unit 104 is a video bit stream to head end 106 from apersonal computer or an outgoing facsimile transmission.

[0048] At stage 804, frames 202 ₁-202 _(X) of data are segmented. Codes118 ₁-118 _(N) may be assigned according to each of segments' 204 ₁₁-204_(XN) position in the original transmitted data stream. For example forsource stream 302 ₁, segment 204 ₁₁ is assigned the highest level ofimportance, segment 204 ₁₂ is assigned the second highest level ofimportance, and continuing to segment 204 _(1N), which is assigned thelowest level of importance.

[0049] At stage 806, partition streams 402 ₁₁-402 _(XN) are created bygrouping segments 204 ₁₁-204 _(XN) with the same associated one of codes118 ₁-118 _(N) and transmitting from the same one of appliances 102₁-102 _(X). Also, in stage 808, divisions representing segments 204₁₁-204 _(XN) are removed so that other divisions, such as blocks 502₁₁₁-502 _(XNZ) can be inserted. The purpose of forming blocks 502₁₁₁-502 _(XNZ) is to resize the divisions, where the size of each ofblocks 502 ₁₁₁-502 _(XNZ) is determined by the bit rate and frame lengthof the data transmitted from a particular one of appliances 102 ₁-102_(X). By removing segments 204 ₁₁-204 _(XN) and creating blocks 502₁₁₁-502 _(XNZ), the respective transmission rates of appliances 102₁-102 _(X) are preserved.

[0050] At stage 810, partition streams 402 ₁₁-402 _(XN) undergo atransformation to form code streams 602 ₁-602 _(N). Code streams 602₁-602 _(N) are created for codes 118 ₁-118 _(N) containing blocks 502₁₁₁-502 _(XNZ). Also, code streams 602 ₁-602 _(N) may contain frames 604₁-604 _(L). One of blocks 502 ₁₁₁-502 _(XNZ) from each of appliances 102₁-102 _(X) is contained within every one of frames 604 ₁-604 _(L). Forexample, in frame 604, all of appliances 102 ₁-102 _(X) will transmitevery one of blocks 502 ₁₁₁-502 _(XNZ) associated with code 118 ₁. Thisensures that when code streams 602 ₁-602 _(N) are spread into SCDMAsignals (stage 812) before being transmitted to head end 106, each ofappliances 102 ₁-102 _(X) is given an opportunity to transmit someportion of the total transmitted data in the event head end 106determines that some of codes 118 ₁-118 _(N) should not transmit. Thecost to each of appliances 102 ₁-102 _(X) is that the loss in bandwidthwill be shared by all transmitting appliances 102 ₁-102 _(X) and notcause the interruption of service to a select few of appliances 102₁-102 _(X).

[0051] Other embodiments will be apparent to those skilled in the artfrom consideration of the specification and practice of the claimsdisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope and spirit of theinvention being indicated by the following claims.

What is claimed is:
 1. A method for partitioning information on a cablenetwork, including one or more appliances and data associated with eachtransmitting appliance, wherein the associated data comprises a bit rateand a frame length, said method comprising: creating a source stream,corresponding to each transmitting appliance and representing acontinuous form of the associated data, containing at least one segment,wherein each segment is associated with one of the transmittingappliances and is assigned a code indicating a predetermined level ofimportance; creating a partition stream, corresponding to each segment,containing at least one block, wherein each block represents an amountof time in relation to the bit rate and frame length of the associateddata; and creating a code stream, corresponding to each block with thesame assigned code, and containing at least one coded frame, whereineach coded frame represents an amount of time to process one block fromevery source stream.
 2. The method of claim 1, wherein the one or moreappliances are coupled to a subscriber unit and creating a code streamfurther comprises the subscriber unit transmitting each code stream to ahead end.
 3. The method of claim 1, wherein the associated data has finegranularity scalability features comprising a base layer and anenhancement layer, the enhancement layer further comprising data that isordered from a greater importance level to a lesser importance level. 4.The method of claim 1, wherein the predetermined level of importance isbased upon a position occupied by each segment within each sourcestream.
 5. The method of claim 1, wherein the cable network uses asynchronous code division multiple access system in compliance withDOCSIS 2.0
 6. A system for partitioning information on a cable network,wherein the cable network includes one or more appliances and dataassociated with each transmitting appliance, wherein the data comprisesa bit rate and a frame length, said system comprising: means forcreating source streams, corresponding to each transmitting applianceand representing a continuous form of the associated data, containing atleast one segment, wherein each segment is associated with one of thetransmitting appliances and is assigned a code indicating apredetermined level of importance; means for creating partition streams,corresponding to each segment, containing at least one block, whereineach block represents an amount of time in relation to the bit rate andframe length of the associated data; and means for creating codestreams, corresponding to each block with the same assigned code, andcontaining at least one coded frame, wherein each coded frame representsan amount of time to process one block from every source stream.
 7. Thesystem of claim 6, wherein the one or more appliances are coupled to asubscriber unit and the subscriber unit transmits each code stream to ahead end.
 8. The method of claim 6, wherein the predetermined level ofimportance depends upon a position occupied by each segment within eachsource stream.
 9. The system of claim 6, wherein the cable network usesa synchronous multiple access system in compliance with DOCSIS 2.0. 10.The system of claim 9, wherein the associated data has fine granularityscalability features comprising a base layer and an enhancement layer,the enhancement layer further comprising data that is ordered from agreater importance level to a lesser importance level.